node.js - 如何在 Node.js 中正确使用 Mongoose 模型？

Question

我正在尝试使用 Mongoose 来控制我的数据库逻辑和事务。我已经获得了架构定义，并且正在导出模型。

但是，当我尝试使用模型时，它会失败并显示如下消息:

return mongoose.model('Report', reportSchema);
} has no method 'find'...

这是我的模型导出:

module.exports = (function() {

var mongoose = require('mongoose'),
Schema = mongoose.Schema,
ObjectId = Schema.ObjectId;

    var reportSchema = mongoose.Schema({

        category: ObjectId,
        authorName: String,
        authorEmail: String,
        text: String,
        address: String,
        coordinates: {
          type: "Point",
          coordinates: [Number,Number]
        },
        date: {
            type: Date,
            default: new Date()
        },

        comments: Array
    });

    return mongoose.model('Report', reportSchema);
});

这就是我的 Controller 函数如何使用 mongoose 进行编码:

module.exports = (function() {

    var mongoose = require('mongoose');
    var Report = require('../models/Report');
    var Category = require('../models/Category');

    function _getReports (request,response,next) {

        var take = request.query.take;
        var skip = request.query.skip;

        Report.find({}).limit(take).skip(skip).exec(function (err,reports) {

            callback(err,reports,response);
        });
    }

    function _getReport (request,response,next) {

        var id = request.params.id;

        Report.findById({_id: id}, function (err,report) {

            callback(err,report);
        });
    }

    function _createReport (request,response) {

        var newReport = new Report();

        newReport.text = request.body.text;
        newReport.category = request.body.category;
        newReport.author = request.session.userId;

        newReport.save(function (err,savedReport) {
            callback(err,savedReport._id,response);
        });

    }

    function _updateReport (request,response) {

        var id = request.params.id;
        var update = request.body.report;

        Report.findByIdAndUpdate(id, update, function (err,foundReport) {

            callback(err,foundReport,response);
        });
    }

    function _deleteReport (request,response) {

        var id = request.params.id;

        Report.findByIdAndRemove(id, function (err,foundReport) {
            callback(err,foundReport,response);
        });
    }

    function _getReports (request,response,next) {

        var take = request.query.take;
        var skip = request.query.skip;

        Report.find({}).limit(take).skip(skip).exec(function (err,reports){

            callback(err,reports,response);
        });
    }

    function _getCategories (request,response) {

        var take = request.query.take;
        var skip = request.query.skip;

        Report.find({}).limit(take).skip(skip).exec(function (err,reports) {

            callback(err,reports,response);
        });
    }

    function _getCategoryReports (argument) {

        var _id = mongoose.Types.ObjectId(request.params.id);

        Report.find({category:id},{category:false},function (err, foundReports) {
            callback(err,foundReports,response);
        });
    }

    function _createCategory (request,response) {

        var newCategory = new Category();

        newCategory.name = request.body.name;

        newCategory.save(function (err,savedCategory) {
            callback(err,savedCategory._id,response);
        });
    }

    function _updateCategory (request,response) {

        var id = request.params.id;
        var update = request.body.category;

        Category.findByIdAndUpdate(id, update, function (err,foundCategory) {

            callback(err,foundCategory,response);
        });
    }

    function _deleteCategory (request,response) {

        var id = request.params.id;

        Category.findByIdAndRemove(id, function (err,foundCategory) {
            callback(err,foundCategory,response);
        });
    }



    function callback (err,object,response) {

            if (err)
                response.status(500).send(JSON.stringify(err));

            response.send(JSON.stringify(object));
    }


    var apiController = {
        getReports: _getReports,
        getReport: _getReport,
        createReport: _createReport,
        updateReport: _updateReport,
        deleteReport: _deleteReport,
        getCategories: _getCategories,
        getCategoryReports: _getCategoryReports,
        createCategory: _createCategory,
        updateCategory: _updateCategory
    }

    return apiController;
})();

在此之前，确保 Mongoose 连接:

var connectToMongoose = function (mongoose,app) {

    var connect = function () {
        var options = { server: { socketOptions: { keepAlive: 1 } } };
        mongoose.connect( 'mongodb://localhost/data4', options);
    }


    mongoose.connection.on('connected', function () {

        console.log('Connected to db');

        app.listen(32884, function() {
          console.log("Listening at \"data4 port\" @:32884");
        });
    })

    mongoose.connection.on('error', function (err) {
      console.log(err);
    });

    mongoose.connection.on('disconnected', function () {
        console.log('Disconnected from db, attempting to connect again...');
        app.close();
        connect();
    });

    connect();
};

module.exports = connectToMongoose;

由 require('./db/mongoose-connect.js')(mongoose,app); 调用

我做错了什么？

Answer 1

我立即发现了几个问题。

首先，我没有看到 mongoose.connect() 行将您的 mongoose ODM 显式连接到 mongo 服务器+数据库。一个例子是:

var mongoose = require( 'mongoose' ),
Schema =        mongo.Schema,
ObjectId =      mongo.Schema.ObjectId;

mongoose.connect( 'mongodb://localhost/db_name' );

您的架构导出看起来不错。但是您使用匿名函数作为导出。既然您这样做了，您的 require 语句需要稍微改变一下:

var Report = require('../models/Report')();
var Category = require('../models/Category')();

注意 require 语句末尾的 ()。您需要执行定义为模型文件的 module.export 的函数。

编辑:我看到您添加了 Mongoose 连接代码。此时，执行您在模型文件中分配的 module.exports 函数应该允许您的 mongoose 模型按预期运行。